The empty lot at 130 North Franklin Street, a prominent location that was once home to the Chicago Mercantile Exchange, is set to be the site of a 48-story office tower designed by Krueck + Sexton. The building, clad in a faceted all-glass curtain wall, will be the Chicago firm’s largest hometown project to date and will tower above its neighbors. “For the last 10 years this has been surface parking just waiting for an opportunity for development,” said firm principal Mark Sexton.

Part of developer Tishman Speyer’s portfolio—which also includes 10 and 30 South Wacker Drive, the Franklin Center, and 161 North Clark Street—the site benefits from a resurgent downtown real estate market, as well as freshly cemented identities in nearby neighborhoods like River North and the Fulton River District. “We heard 20 years ago that the Loop was dying,” said Sexton. “We heard it again 10 years ago. It’s a bit like retail—people thought with the Internet that no one would buy at stores anymore, but look at retail booming.”

The previous occupant of the site—a 1927 masonry structure with a rusticated base and engaged columns at its crown—was demolished in 2003, leaving a somewhat conspicuous opening in a corridor of the Loop just steps from Ogilvie Transportation Center, Merchandise Mart, and City Hall.

Krueck + Sexton’s design is an evolution of the faceted facade treatment the firm used on the Spertus Institute of Jewish Learning and Leadership, also in Chicago. The unitized curtain wall system is made up of an assemblage of sections that intersect at angles calculated to reflect the sky in varying ways, creating a play of varying qualities of light across an otherwise homogeneous envelope. The design team is still tweaking the interplay between the facade and mechanical systems, but Sexton said that the goal is to achieve a LEED Gold rating.

Two landscaped plazas (the firm hasn’t chosen a landscape architecture consultant at this time) open onto Franklin and Washington Streets. The lobby, with its 50-foot-high ceiling, has multiple entrances. “This is going to be a major building on Franklin,” Sexton said, “so the idea was to have a lofty opening befitting a building of 1.1 million square feet.”

The building’s podium includes 13,000 square feet of retail and a parking garage with 200 spaces. Office floors offer between 25,000 square feet and 27,000 square feet. A “SkyPark” on the seventh floor juts northward from the building, adding some open space to the dense downtown business district. The fifth and sixth floors share an 87,000-square-foot courtyard and atrium.

The concrete core supports column-less corners, with floor-to-ceiling glass on all sides. Tishman needs to lease at least 400,000 square feet before proceeding with construction. Sexton said he told the developers his firm would take a few thousand square feet, but with no anchor tenant targeted he’s off the hook for the time being.

Construction will take 24 to 30 months once started, according to Tishman Speyer.